448 The action of drugs on circulatory disturbances in the rabbit heart due to anaphylactic conditions

448 The action of drugs on circulatory disturbances in the rabbit heart due to anaphylactic conditions

134 ilbstracts plegic drugs, aminazine will likewise depress these while reserpine suppresses serotonininduced reflex bradycardia, but exerts no de...

119KB Sizes 7 Downloads 97 Views

134

ilbstracts

plegic

drugs, aminazine will likewise depress these while reserpine suppresses serotonininduced reflex bradycardia, but exerts no definite influence on cardiac deceleration caused by veratrine. As substances eliciting coronary chemoreflexes may form in the heart itself when the coronary circulation is disturbed, it was decided to test the influence of analgesic and neuroplegic agents on the reflex changes of circulation brought about by limiting the coronary blood-flow. It was found that the above agents will decrease the reflex response to clamping of the coronary artery. Analgesic and nelwoplcgic drugs will likewise decrease the reflex contraction of the coronary vessels when the afferent nerves are stimulated. The coronary chemoreflexrs have much in common with the reflexes in response to chemical stimulation of the lungs. reflexes,

447 The Inlluence of Pharmacological Agents on the Reflex Reactions of Coronary Vessels. N. v. JL\\.ERINA (U.S.S.R.).

of Papers 448 The Action of Drugs on Circulatory Disturbantes in the Rabbit Heart due tb Anaphylactic Conditions. E. BUSCH (Germany). Exploration of coronary vasodilawrs is complicated by the fact that experimental conditions arc required which imitate as far as possible pathological conditions in man. In thr proteinsensitized rabbit, conditions are very similar to human coronary circulatory disturbances. .%part from myocardial changes, the coronary \-essels are damaged severely which results in circulatory disturbances in the myocardium, changes in the electrocardiogram, and hypotension if a shock iy induced. These symptoms can be observed during an angina1 attack or during the development of an infarct. I-fi-ethoxyphenyl-3-diethylamino-inclan which has been developed in our laboratories i\ a coronary active substance and comprnsates consequences of a shock or, if given bcforr the shock, will prevent symptoms. Comparative trials with \rasopressin or ergometrin, used until no<\‘ to induce a spasm, have shown that this drug causes myocardial disturbances, but does not alter general circulation correspondingly. (It must be mentioned here that vasopressin and ergoInctrin-inducctl spasms can also be compensated by the above new substance.) The difference between the two forms of circulatory disturbances may be explained by the fact that vasopressin and ergometrin spasms affect a healthy organ which has sufficient reserves to tolerate this stress for a certain time. Howwrr, functional coronary constriction \&&out pathological changes ofvessels and heart murcle-so-called angina pectoris vasomotorica-is rather controversial, therefore, these tests are only of limitrd value when the coronary activity of a substance is to be judged. Today an anaphylactic process as thl, cause of human coronary disturbances iy frequently discussed. Hence, we are of the opinion that an anaphylactic myocardial ischemia in the rabbit is particularly suitable to study the effectiveness of coronary vasodilatators.

One of the ways of normalizing the cardiac blood supply ccnsists in suppressing reflex reactions causing contraction of the coronaries with theaid of pharmacological agents. The aim of the present investigation was to study the influence of pharmacological agents on the reflex reactions of the coronaries following stimulation of the receptors of the carotid sinus and of the afferrnt nerves. ;Is has been shown earlier by us, certain compounds of the phenothiazine series (chloracyaine, mepazine and to a lesser extent aminazine) increase the cardiac blood supply. It seemed interesting to elucidate the role played of these agents in the reflex reactions of the coronaries tending to return the blood supply the mvocardium to normal. It was found that amina&e and mepazine cause considerable depression of the reflex reactions of the Chloracyzine’s influence on these rc- 449a Mode d’Action des Inhibiteurs de la Monocoronaries. actions is inconstant. Apparently, thr normalizing Amine-Oxydase SW le Systeme Cardioeffect on the coronary circulation exerted by the Vasculaire-Relations avec la Structure phcnothiazine compounds studied is due to different Chimique. J. CAHN, hl. HEROLD, N. BARRE, mechanisms. 0. KABACOFF and I. BAMBEKGER (Franc?). r\nalgesic agents (morphine, thecodin, promedol, phenadon) in doses corrrsponding to those used Lrs auteurs ont etudit lcs effets SW le syst&ne therapeutically, depress the reflex reactions of the cardio-vasculaire de diff&ents inhibiteurs de la cardiac vessels. Nitroglycerine depresses considermono-amine-oxydase (Hnrmaline, Slarsilid, Terably the reflexes reactions, though it does not alter savid, Marplan, RO 4 1038, RO 4 2637, Niamide, PC 603, PC 607, PC 610, PC 614) : les effets pharmaterially either the minute volume of the coronary blood flow or the resistance of the cardiac vessels. macologiques de ces inhibiteurs de la mono-amineThis effect is due to the influence it exerts on the oxydase sur le systeme cardio-vasculaire et l’ttude de la dynamique et du metabolisme cardique ont central nervous system. Thus, the property of pharmacological agents to ttC ttudits chez 60 chiens; les effets de ces m&mes drogues sur les modifications E.C.G. provoqu& alter the intensity of the coronary reflexes may be par la vasopressine ont et& recherch& sur 100 an important link in the mechanism of their influlapins; I’action de ces mZmes drogues sur ia n&row ence on the cardiac blood supply.